1. Field of the Invention
The present invention relates to an organic light emitting device, and more particularly, to a white organic light emitting device and a display device using the same to which a 2-peak spectrum is applied to execute white display.
2. Discussion of the Related Art
Recently, as the information age has arrived in earnest, a display field to visually express electric information signals has rapidly developed. In order to satisfy such a trend, various flat display devices having excellent performance, such as a thin profile, a light weight, and low power consumption, have been developed and have quickly replaced conventional cathode ray tubes.
As examples of the flat display devices, there are liquid crystal displays (LCDs), plasma display panels (PDPs), field emission displays (FEDs), and organic light emitting devices (OLEDs).
Among the above flat display devices, organic light emitting devices are considered as a competitive application to achieve compactness and clear color display of the devices without a separate light source.
These organic light emitting devices essentially require formation of an organic light emitting layer, and a deposition method using a shadow mask has been conventionally used to form the organic light emitting layer.
However, if the shadow mask has a large area, the shadow mask sags due to load thereof and thus it is difficult to use the shadow mask several times, and an error may occur during formation of an organic light emitting layer pattern. Therefore, methods to solve these problems are required.
As one of several methods substituted for the shadow mask, a white organic light emitting display device is used.
Hereinafter, the white organic light emitting display device will be described.
The white organic light emitting display device is formed by depositing respective layers between a cathode and an anode without a mask during formation of light emitting diodes. Here, organic films, such as an organic light emitting layer, having different components are sequentially deposited in a vacuum state.
The white organic light emitting display device is used for various purposes, e.g., as a thin light source, a backlight of a liquid crystal display device, and a full color display device employing color filters.
In general, a spectrum applied to the white organic light emitting display device generally has 3 peaks or more such that respective peaks are generated at R, G and B regions to achieve color implementation. The reason for this is to relatively facilitate RGB color implementation of light transmitted through a light emitting layer after transmission through a color filter layer.
As a structure of the white organic light emitting display device, a 2 tandem structure including a blue light emitting unit and a red-green light emitting unit is well known. However, it is not easy to simultaneously emit red light and green light from the red-green light emitting unit, and to reproductively obtain light intensities of corresponding peaks of the red light and the green light during a process.